As the minor league season draws to a close, let's review those prospects who have done the most to improve their stock in 2012, as well as those phenoms who have lost some of their luster. This list is not meant to be all-inclusive and is by no means a ranking of minor leaguers.

Dylan Bundy, P, BAL - Everyone knew Bundy was good when he was selected straight out of high school with the No. 4 overall pick in the 2011 draft. However, it's not certain everyone knew he would be THIS good. Bundy did not allow an earned run in his first 30 professional innings, posting a 40:2 K:BB ratio at Low-A Delmarva this season. He moved on to High-A, where he was no less impressive, compiling a 2.84 ERA and 66:18 K:BB ratio in 57 innings. At 19, he is now already at Double-A Bowie and has more than held his own through three starts. Heading into 2013, he is arguably the top pitching prospect in the minors.Billy Hamilton, SS, CIN - An absolute terror on the basepaths, all Hamilton has done this year is steal 155 bases, breaking Vince Coleman's minor-league record of 147. Perhaps more important, though, Hamilton has improved his plate discipline, posting a .311 batting average and .410 OBP in 132 games between High-A and Double-A. He'll never hit for much power, but that's not a huge concern considering he turns most singles into doubles anyway via the stolen base. If Hamilton can cut his strikeouts just a bit more, he could be the next great leadoff hitter in the majors.Delino DeShields Jr., 2B, HOU - If not for Hamilton's season, more people may have taken notice of DeShields, a 20-year-old speedster who swiped 101 bases between Low-A and High-A. Unlike Hamilton, though, DeShields has shown home run power, too, bashing 12 dingers while knocking home 61 runs in 135 games in 2012. DeShields has fanned 131 times this year, but has also shown the ability to draw a walk with 83 free passes. If he can keep his batting average up, DeShields could follow in Hamilton's footsteps.Oscar Taveras OF, STL - Taveras proved his .386 batting average from 2011 was indeed a great sign of his potential, parlaying his Low-A success directly to Double-A in 2012. This season, the 20-year-old lefty slashed .321/.380/.572 with 23 home runs, 94 RBI and 10 stolen bases in 124 games. Taveras hit .305 against lefties, furthering the notion that he is the real deal. The Cardinals have a crowded outfield, but it will be tough to keep him down in 2013 if he continues to rake.
CHECK STATUS

Alen Hanson, 2B, PIT - Hanson came from virtual anonymity to have a sensational campaign at Low-A West Virginia, firmly placing himself on the prospect map. Hanson is hitting .309/.381/.528 with 16 home runs, 62 RBI and 35 steals in 124 games for the Power. Hanson slowed as the season wore on, and questions remain as to whether he can keep this up at the higher levels, particularly due to his small frame. However, there's no denying the production, as Hanson's combination of power, speed and plate discipline makes him an intriguing prospect heading into 2013.Chris Heston, P, SF - Heston was recently named the Eastern League Pitcher of the Year, compiling a 2.24 ERA and 135:40 K:BB ratio in 148.2 innings at Double-A Richmond. A groundball pitcher, Heston sported a 1.63 GO:AO ratio this season, allowing just two home runs the entire 2012 campaign. Heston will turn 25 next April, was a 12th-round pick in 2009 and was not regarded as one of the Giants' best prospects entering 2012. Still, it appears he may get his shot at the bigs in 2013, as he has been successful at nearly every stop in the minors despite the lack of fanfare.Trevor May, P, PHI - On pure stuff, May can be overwhelming at times, as witnessed by his 151 strikeouts in 149.2 innings for Double-A Reading. However, he has not been able to translate those strikeouts into all-around production, as May has a 4.87 ERA with 78 walks in 2012. He has also been snake-bitten by the long ball, having served up 22 home runs this season. The 22-year-old has the size and stuff to be an elite pitcher, but the end product in 2012 was certainly not indicative of a front-line starter. Control will be the primary focus for May in 2013.
Tony Cingrani, P, CIN - Cingrani turned in a dominant 2012 campaign, notching a 1.73 ERA and 172:52 K:BB ratio in 146 innings between High-A and Double-A. The 23-year-old southpaw held opposing hitters to a paltry .191 BAA. Despite this runaway success, many still view Cingrani as best suited for a relief role in the majors due to his lack of a true plus-breaking pitch. Still, he hasn't met much resistance as a starter thus far in his brief minor league career, so the Reds likely will leave him in the starting rotation until further notice.
DOWNGRADE

Julio Teheran, P, ATL - Teheran has been perhaps one of the biggest disappointments of the 2012 season. After a posting a 2.55 ERA and 122:48 K:BB ratio in 144.2 innings at Triple-A as a 20-year-old in 2011, the wheels fell off in 2012. Teheran has a bloated 5.08 ERA and 97:43 K:BB ratio in 131 innings this season. Opposing batters are hitting more than 50 points higher against him this season than in 2011. Due to his struggles, he was continuously passed over for promotions during the 2012 campaign despite the Braves searching for adequate starting pitching. Teheran is still young, but his star definitely faded a bit this year.Dellin Betances, P, NYY - If Teheran's season has been bad, Dellin Betances' year has been catastrophic. The 6-foot-8, 260, righty was incredibly wild at Triple-A, accumulating a 71:69 K:BB ratio en route to a 6.39 ERA in 74.2 innings. Betances was so awful that he was demoted to Double-A in hopes of regaining his confidence. Unfortunately, that didn't work either, as the 24-year-old had a 6.51 ERA for Double-A Trenton, with opposing batters hitting a crisp .319 against him. The 2012 campaign ended with a trip to the disabled list due to right shoulder soreness. Once part of the vaunted "Killer B's" for the Yankees, Betances is searching for answers heading into 2013.Mike Montgomery, P, KC - Arguably the top pitching prospect in the Royals organization entering the season, Montgomery is also trending in the wrong direction. Starting the season at Triple-A Omaha, Montgomery had a 5.69 ERA and 67:43 K:BB ratio in 91.2 innings. The constant tinkering with his mechanics clearly took a toll on the 23-year-old lefty, who was sent to Double-A with even worse results. In 10 starts at Double-A Northwest Arkansas, Montgomery notched a 6.67 ERA. In total, Montgomery has allowed a staggering 24 home runs in 2012. Montgomery appears to have hit a wall in both his production as well as his development, as this is his second year in a row with disappointing statistics.Zack Cox, 3B, MIA - Cox has failed to live up to expectations this season, resulting in a trade from St. Louis to the Marlins at the deadline. The No. 25 overall pick in the 2010 draft slashed .254/.294/.421 with nine home runs and 30 RBI in 84 games for Triple-A Memphis before the deal. Upon his arrival to the Marlins, he was sent to Double-A instead of Triple-A, with similar mediocre results. Cox is batting .253/.321/.368 with one home run and 13 RBI through 24 games for Double-A Jacksonville. Although his path to the big leagues is not blocked, Cox is going to have to improve his plate discipline and show more pop to become a viable option for both the Marlins and fantasy owners alike.